the hole on the wall is a door. it is north of room1 and below room2.
before going north from room1:
if the player is in room1:
say "You enter in the hole on the wall. You walk in a narrow tunnel for a while, than you reach a wooden ladder. You start climbing it.".
before entering in the hole on the wall:
if the player is in room1:
say "You enter in the hole on the wall. You walk in a narrow tunnel for a while, than you reach a wooden ladder. You start climbing it.".

but if the player while he is in room1 writes
nord
it prints

nord
You enter in the hole on the wall. You walk in a narrow tunnel for a while, than you reach a wooden ladder. You start climbing it.

Room2
Description of room2.

and if he writes
enter in hole on the wall
it prints

nord

Room2
Description of room2.

??? what’s the problem???
It is important because if the player read “there is a hole on the northern wall”, he probably won’t write “nord”, but “enter in the hole”…

The action name for entering would be “entering the hole in the wall.” (The action name is “entering” followed by the noun.) When you type “Entering in the hole in the wall,” Inform basically understands that as “before (entering) (in the hole in the wall)”–which is to say “before entering [something, anything] [when the player is] in the hole in the wall”–which never happens, because the player can never actually be in the hole in the wall.

By the way you don’t need the if-clause in the first rule–since you have “from room1” in the room heading, you don’t need another check that the player is in room1.

The action name for entering would be “entering the hole in the wall.” (The action name is “entering” followed by the noun.) When you type “Entering in the hole in the wall,” Inform basically understands that as “before (entering) (in the hole in the wall)”–which is to say “before entering [something, anything] [when the player is] in the hole in the wall”–which never happens, because the player can never actually be in the hole in the wall.

By the way you don’t need the if-clause in the first rule–since you have “from room1” in the room heading, you don’t need another check that the player is in room1.

ahhh ok ok I understood, so it should be something like “entering through the hole in the wall”?

The action name for entering would be “entering the hole in the wall.” (The action name is “entering” followed by the noun.) When you type “Entering in the hole in the wall,” Inform basically understands that as “before (entering) (in the hole in the wall)”–which is to say “before entering [something, anything] [when the player is] in the hole in the wall”–which never happens, because the player can never actually be in the hole in the wall.

By the way you don’t need the if-clause in the first rule–since you have “from room1” in the room heading, you don’t need another check that the player is in room1.

ahhh ok ok I understood, so it should be something like “entering through the hole in the wall”?

Just for posterity’s sake, since the other approach worked, you would write this:

before entering the hole on the wall:
if the player is in room1:
say "You enter in the hole on the wall. You walk in a narrow tunnel for a while, than you reach a wooden ladder. You start climbing it.".

The action name for entering would be “entering the hole in the wall.” (The action name is “entering” followed by the noun.) When you type “Entering in the hole in the wall,” Inform basically understands that as “before (entering) (in the hole in the wall)”–which is to say “before entering [something, anything] [when the player is] in the hole in the wall”–which never happens, because the player can never actually be in the hole in the wall.

By the way you don’t need the if-clause in the first rule–since you have “from room1” in the room heading, you don’t need another check that the player is in room1.

ahhh ok ok I understood, so it should be something like “entering through the hole in the wall”?

Just for posterity’s sake, since the other approach worked, you would write this:

before entering the hole on the wall:
if the player is in room1:
say "You enter in the hole on the wall. You walk in a narrow tunnel for a while, than you reach a wooden ladder. You start climbing it.".